The present invention relates to making viscoelastic compositions.
Methods of making packaged viscoelastic compositions such as hot melt adhesives and the resulting packaged compositions are known. German Patent No. 36 25 358 describes a hot melt adhesive block in a thermoplastic film. The film is melted and mixed with the adhesive in an extrusion process.
U.S. Pat. No. 5,257,491 describes a method of packaging a thermoplastic or thermosetting hot melt adhesive in which a portion of an adhesive composition is surrounded with a plastic packaging material. The plastic packaging material does not substantially adversely affect the adhesive characteristics of a molten mixture of the adhesive and the plastic packaging material.
PCT International Publication No. WO 93/23224 describes a method for packaging hot melt adhesive compositions in which molten hot melt adhesive is poured into a mold lined with a plastic film. The plastic film is meltable with the adhesive composition and blendable into the molten adhesive composition.
A method for producing thermoplastic mold materials useful for producing molded articles is described in German Patent Disclosure 1 694 837, published Jul. 29, 1971. In the described method, the polymerization material is allowed to polymerize in a hollow profile that functions as a polymerization vessel. The hollow profile may be made of the same polymer produced in the polymerization process.
Methods of producing hot melt adhesives in sealed reaction vessels are known. U.S Pat. No. 4,810,523 describes a method for producing hot melt adhesives in which a polymerizable monomer composition is introduced into a sealable reaction vessel and polymerized by ionizing radiation. The adhesive is then removed from the reaction vessel before hot melt application. The reaction vessel may be a lined cylindrical pressure vessel or a multilayer bag. See column 8, line 58, to column 9, line 8, of U.S. Pat. No. 4,810,523.
Although methods of producing viscoelastic compositions such as hot melt adhesives and methods of packaging such compositions are known, there is a need for a simplified process for making such compositions.